Question: Reduce to lowest terms: $ \dfrac{9}{4} \div \dfrac{1}{7} = {?}$
Explanation: Dividing by a fraction is the same as multiplying by the reciprocal of the fraction. The reciprocal of $ \dfrac{1}{7}$ is $ \dfrac{7}{1}$ Therefore: $ \dfrac{9}{4} \div \dfrac{1}{7} = \dfrac{9}{4} \times \dfrac{7}{1} $ $ \phantom{ \dfrac{9}{4} \times \dfrac{7}{1}} = \dfrac{9 \times 7}{4 \times 1} $ $ \phantom{ \dfrac{9}{4} \times \dfrac{7}{1}} = \dfrac{63}{4} $